In the past week, there's been a lot of talk of the need for "adult conversations" about government spending, so let's have one about Provenge. That's the name of a new treatment for advanced prostate cancer that federal officials are currently reviewing to see if it will be covered by Medicare and Medicaid. Provenge, a study shows, increases survival for advanced prostate cancer patients — by an average of four months. Its cost: $90,000 for those four months of treatment. Is it worth that much to give a terminally ill person a few more months? It sure as hell is, if it's your life, or that of someone you love. For the hopeless, hope is never too expensive. But as H. Gilbert Welch of the Dartmouth Institute for Health Policy told The Washington Post last week, the question becomes more complicated if society has a finite number of health-care dollars to spend. ''That’s $100,000 Medicare can’t spend elsewhere," Welch says. Multiply Provenge by, say, 30,000 patients a year, and you get $2.7 billion. Multiply that by other expensive new cancer therapies, prescription drugs, and other medical treatments, and you get monstrous health-care costs that are swallowing much of our national wealth.

So what do we do? If we impose coldly rational limits on health-care spending, we're engaged in rationing. If we refuse to limit spending on health care — or on Social Security or national defense or education — because such limits will cause distress, suffering, and outrage, then we've decided to keep spending trillions we don't have, endlessly. There's a name for people who won't accept that life is difficult, and that hard choices must be made. We call them children.